Shredding machine

ABSTRACT

A plurality of shredding or beater blades are attached to a shaft which is coaxially journalled within a hollow cylindrical shredder drum. A motor is coupled to the shaft for rotating the blades. An annular inlet spout is attached to the upper end of the drum and projects downwardly therewithin, there being an annular whirl space or trap for whirling debris between the inlet spout and the inner surface of the drum. The bottom of the inlet spout is spaced from the nearest shredding blade to provide a debris recirculation zone above said blade. The shredded material drops or is blown out the bottom of the shredder drum onto the ground or into a storage receptacle.

Unite States Enters et al.

atent [191 41 SHREDDING MACHINE [75] Inventors: Edward W. Enters,Fredonia; Edgar W. Detjen, Kiel, both of Wis.

[73] Assignee: Gilson Bros. Co., Plymouth, Wis.

[22] Filed: Aug. 8, 1973 [21] Appl. No.: 386,807

[52] US. Cl. 241/55, 241/101.7, 241/186 R, 241/188 R [51] Int. Cl. B02c13/14 [58] Field of Search..... 241/37.5, 55, 101.7, 101 M, 241/186 R,186.1, 188 R Jan. 14, 1975 3,716,090 2/1973 Lautzenheiser 241/101.7 X3,726,488 4/1973 Aasland et a1. 241/10l.7 3,727,847 4/1973 Nelson241/101 M Primary ExaminerGranville Y. Custer, Jr. AssistantExaminerl-loward N. Goldberg Attorney, Agent, or FirmJoseph P. House,Jr.

[57] ABSTRACT A plurality of shredding or beater blades are attached toa shaft which is coaxially journalled within a hollow cylindricalshredder drum. A motor is coupled to the shaft for rotating the blades.An annular inlet spout is attached to the upper end of the drum andprojects downwardly therewithin, there being an annular whirl space ortrap for whirling debris between the inlet spout and the inner surfaceof the drum. The bottom of the inlet spout is spaced from the nearestshredding blade to provide a debris recirculation zone above said blade.The shredded material drops or is blown out the bottom of the shredderdrum onto the ground or into a storage receptacle.

10 Claims, 6 Drawing Figures PATENTEB JAN I 41975 SHEET 18F 3 SHREDDINGMACHINE BACKGROUND OF THE INVENTION This invention relates to machinesfor shredding, composting or otherwise comminuting waste material andparticularly organic material such as leaves, twigs, garbage and thelike. The principal objects of this invention are to provide a novelshredding machine which is easier to use and is more effective thanthose heretofore known in the art. Other objects of the invention are toprovide a shredding machine which is simple and sturdy in structure andrelativelyinexpensive in cost.

SUMMARY OF THE INVENTION The above-noted objects are achieved byproviding a hollow cylindrical shredder drum, a shaft coaxiallyjournalled within the drum, at least one shredding or beater bladeattached to the shaft and projecting radially therefrom, means forrotating the shaft and shredding blade, an annular inlet spout attachedto the upper end of the drum and projectingdownwardly therewithin, therebeing an annular whirl space or debris trap between the outer surface ofthe inlet spout and the adjacent inner surface from the shredding bladeto provide a debris recirculation zone above said blade.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of oneillustrative embodiment of the invention;

FIG. 2 is a longitudinal cross-sectional view of the embodimentillustrated in FIG. 1;

FIG. 3 is a front view of the embodiment shown in FIGS. 1 and 2 with oneside of the housing being cut away to expose interior details;

FIG. 4 is a rear view of the embodiment shown in FIGS. I-3 with the rearwall being cut away to expose interior details;

FIG. 5 is a cross-sectional .view of a second embodiment of theinvention;

FIG. 6 is a cross-sectional view taken on the line 6-6 of FIG. 5.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Although the disclosure hereofis detailed and exact to enable those skilled in the art to practice theinvention, the physical embodiments herein disclosed merely exemplifythe invention which may be embodied in other specific structure. Thescope of the invention is defined in the claims appended hereto.

FIGS. 1 through 4 show one embodiment of the invention which isspecifically adapted for shredding leaves and the like. Referring toFIG. I, this embodiment comprises an outer housing 10 which is movablysupported on the rear end by wheels 12 and is fixedly supported on thefront end by a flat bottom 14. A pair of handles 16 is attached to thefront side walls of housing 10 so that the front end can be picked up towheel the device from place to place. A small internal combustion engine18 is mounted on top of the housing 10 to drive the shredder mechanism,which is located within the housing 10, and a clutch actuating lever 20projects from the side of housing 10 for controlling the engagement ofthe engine 18 with the shredder mechamsm.

Referring to FIG. 2, the shredder mechanism includes a hollow,cylindrical shredder drum 22 which is mounted within housing 10, abeater mechanism including a shaft 24 which is coaxially journalledwithin shredder drum 22, and three shredder blades 26, 28 and 30 whichare angularly spaced from each other and are attached at axially spacedlocations along shaft 24. The shaft 24 is journalledto a supportingbracket 32 which is attached to the sides of drum 22 and extends acrossthe bottom thereof as best shown in FIG. 4. The supporting bracket 32 isangled downwardly on both sides from the bottom of drum 22 and has anaxially spaced cross brace 34 connected thereacross (see FIG. 4) to helpsupport the shaft 24. A drive pulley 36 is attached to shaft 24immediately above the cross brace 34.

The output of engine 18 is developed as rotation of an output pulley 38(see FIG. 2) which is coupled to drive pulley 36 by a flexible drivebelt 40. The drive belt 40 passes over a fixed guide pulley 42 (see FIG.4) and a movable guide pulley 44 which serves asa clutch for engagingand disengaging the drive belt 40 with the pulleys 36 and 38. Movablepulley 44 is rotatably mounted on a plate 46 which is movable between aposition in which pulley 44 applies pressure'to drive belt 40 so that itengages pulleys 36 and 38 and an opposite position in which pulley 44allows belt 40 to go slack so that it disengages from pulleys 36 and 38.Plate 46 is moved between its twopositions by clutch actuating lever 20and is maintained in the selected position by an expansion spring 48,which draws plate 46 either upwardly or downwardly depending on theplates position.

An annular inlet spout 50 is attached to the upper end of shredder drum22 and projects downwardly therewithin. The outside diameter of spout 50is smaller than the inside diameter of drum 22 so that an annular airspace 52 is left between the outside surface of spout 50 and the insidesurface of drum 22. Air space 52 permits the air within the upperportion of drum 22 to rotate in a cyclonic manner, which is an importantfeature of this invention. Another important feature of the invention isthat the lower edge 54 of spout 50 is sufficiently spaced from thenearest shredder blade 26 to provide a recirculation zone 56 in whichthe material dropped into inlet spout 50 can be recirculated above theshredding blades until it has been completely shredded thereby. Ananti-rotational stop 51 is welded to the side of spout 50 to preventrotation of sticks or twigs that project beyond spout 50.

In this embodiment of the invention, the lowermost shredding blade 30also functions as an impeller, as it is bent at its end 31 to provide amoderate exhaust draft for moving the shredded material axiallydownwardly away from the shredding blades and toward the dis-- chargeend of the housing 10. An elliptical outlet conduit 58 is attachedaround the bottom of drum 22 and extends substantially horizontallywithin housing 10 and terminates in a lipped discharge throat 60 whichis preferably adapted to receive the open end of a collection bag 62.The outlet conduit 58 is slotted in its upper surface at 64 to permitentry of the drive belt 40 therethrough. In the operation of thisembodiment, the shredded material is carried along the bottom ofconduit'58 and into the bottom of bag 62 by the exhaust draft from thebent shredding blade 30. The exhaust draft then circulates around thetop of bag 62 and exits through the slots 64 in the top of outletconduit 58.

In this embodiment of the invention, the axis of shredder drum 22 andshaft 24 is preferably tilted at an angle of approximately 45 degrees tothe vertical to reduce the charging height and to allow leavesand otherinput material to be conveniently swept into inlet spout 50 up 'a rampor chute 66 which is pivotally connected to the inlet spout 50 on hinge67. Chute 66 has upstanding sides 68 and is movable between a loweredramp position which is illustrated in FIG. 2 and two raised chutepositions, one of which is illustrated in FIG. 1. A rectangularly shapedbrace 70 is pivotally attached to the lower front end of chute 66 onhinge 72 and is shaped at its lower corners to provide feet 74 to engagein socket openings 76 and 78 in bottom 14 to support chute 66 indifferent positions above bottom 14. When the lower corners 74 areengaged in openings 76, chute 66 is supported in an approximatelyhorizontal position. When the lower corners 74 are engaged in openings78, chute 66 is supportedin a slightly raised position as shown in FIG.1 for gravity discharge of deposited material into hopper 22.

The top of housing is extended at 80 over a portion of the inlet spout50 to partially cover the same and a hood 82 having a hinged inlet flap84 covers a further portion of the inlet spout 50. The hinged inlet flap84 swings both inwardly and outwardly and is dimensioned to partiallyclose the inlet opening when chute 66 is in its upper most position asshown in FIG. 1. In this position, the inlet flap 84 will swing inwardlyunder the pressure of leaves, twigs or other input material but willblock returnflow and will prevent the twigs, etc., from being thrownback out the inlet opening after being struck by the shredding-blades.

In the lowermost position of chute 66, as shown in FIG. 2, the inletflap 84 does not completely close the inlet opening, but it does coverthat part of the opening which is directly above the inlet spout 50, andhence still protects against twigs or other hard materials from beingthrown out the inlet opening. Articles which are thrown from theshredding blades out the inlet spout 50 must emerge at such an anglethat they will strike either the top housing 80, the inlethood 82, orthe inlet flap 84. Flap 84 also is in the path of hand movement into thedrum and reminds the operator of this danger.

The shredded material moves at a lower speed axially than it would if itwas discharged radially or centrifugally. Hence its exit velocity is lowenough to minimize the likelihood for puncture of the bag 62.

The slant axis of shaft 24 and drum 22 brings the lower lip of chargingspout 50 close to the ground level so that debris is not lifted veryhigh in sweeping it up the ramp 66. Concurrently the upper edge of thebottom of drum 22 is elevated, thus to provide the discharge path intobag 62. Accordingly, the profile of the machine is kept low, yet all therotating parts are well within the housing for safety reasons. The flowpath of debris is straighter than it would be if the axis were vertical,and less work is required to process debris through the machine.

FIGS. 5 and 6 show a second embodiment of the invention in which theaxis of the shredder drum and shaft are vertical. This embodiment isadapted to handle somewhat heavier material than the previouslydescribed embodiment. Referring to FIGS. 5 and 6, this embodimentincludes a hollow, cylindrical shredder drum 86, a hollow shaft 88 whichis coaxially journalled within drum 86 about a'solid shaft 90, and threeshredder blades 92, 94 and 96 which are attached to hollow shaft 88 ataxially spaced location therealong and are angularly spaced from oneanother as shown in FIG. 6. A Safety disc 98 is attached to the top ofshredder blade 92 and rotates therewith. The safety disc 98 protects theoperator from injury in the event that he places his hand withinshredder drum 86 and also serves to deflect input material toward theperiphery of shredder drum 86. A diamond shaped cutting grid 100 ispreferably attached around the periphery of shredder drum 86 in theneighborhood of shredder blades 92, 94 and 96 to assist in shredding theinput material.

The solid shaft 90 which supports hollow shaft 88 is supported at itslower end by supporting members 102 which are connected between crossbraces 104. The cross braces 104 are attached to the inside of shredderdrum 86 and extend thereacross. For the purpose of rotating the hollowshaft 88 and shredding blades 92, 94 and 96, a drive pulley 106 isattached to hollow shaft 88 near its lower end. A drive belt 108 whichis driven by a suitable power source is directed around drive pulley 106by guide pulleys 110. The drive belt 108 may be driven by an internalcombustion engine such as disclosed in FIGS. 1 and 2, an electric motoror by any other suitable power source. The device may be supported on abracket mounted on a garden tractor, in which case-the belt 108 may bepowered from the tractor power take off. Guide pulleys 110 would thenequate to the mule drive of the tractor.

The upper surface of drive pulley 106 is covered by a round cover plate112 which is larger in diameter than pulley 106 to prevent shreddedmaterial from falling into the pulley. Cover plate 112 is clamped to thehub of drive pulley 106 by machine screws 113. The drive belt 108 iscovered by a housing 114 which prevents the shredded material fromfalling onto the drive belt. The housing 114 is shaped to cover both thetop and sides of drive belt 108 and is supported by the cross braces104.

At the upper end of shredder drum 86, an annular inlet spout 116 isattached to the upper inner periphery of drum 86 via a vertical collarportion 118 and a sloping shoulder portion 120. The outer diameter ofinlet spout 116 is substantially smaller than the inside diameter ofshredder drum 86 so that an annular air space 122 is left between theoutside surface of inlet spout 116 and the inside surface of shredderdrum 86. Air space 122 permits the air within the upper portion of drum86 to rotate in a cyclonic manner, which is an important feature of thisinvention. Another important feature of this invention is that the loweredge 124 of inlet spout 116 is sufficiently spaced from the nearestshredder blade 92 to provide a recirculation zone 126 in which thematerial dropped into inlet spout 116 can be recirculated above theshredder blades until it has been completely shredded thereby. Toprevent large sticks and twigs from rotating with the shredder blades,an anti-rotational stop rod 127 extends across recirculation zone 126.Rod 127 is removably attached to the wall of shredder drum 86 bybrackets 129 and 131.

In the operation of this embodiment, the material to be shredded isdropped into inlet spout 116, then bounces off safety disc 98 or isthrown off by centrifugal force toward the wall of shredder drum 86. Thematerial is then struck by upper shredder blade 92, which cuts a pieceoff the material and knocks it back up into recirculation zone 126. Thematerial repeatedly falls back down into the path of shredder blade 92and is knocked back up into recirculation zone 26 until it is smallenough to fall past shredder blade 92. The pieces which are cut off byshredder blade 92 fall down into the path of shredder blades 94 and 96and are further shredded thereby. The pieces which are thrown byshredder blades 94 and 96 against the inner surface of drum 86 are alsoshredded by the diamond shaped cutting grid 100. The shredded peicesfall down through the open bottom of shredder drum 86 onto the ground orinto a suitable collector bag or box which is not shown in the drawings.

The air spaces 52 (FIG. 2) and 122 (FIG. 5) comprise annular whirlspaces or debris traps within which debris may recirculate or whirl andyet be trapped against exiting through the spout. In the case of largetwigs, sticks, or the like, they are prevented from rotating byanti-rotational stop elements 51 and 127. This causes the large piecesto be quickly shredded by the shredding blades.

The slot or hole 64 in the top of outlet conduit 58 in FIG. 2 isadvantageously located to exhaust air from the bag 62 within which dustand debris is trapped and collected and is isolated from contact withthe operator.

Both illustrated embodiments are adapted to convert various items ofvegetable or organic matter such as garbage, leaves, twigs and othervegetation into finely chopped discrete particles which can be compostedor otherwise easily disposed of or utilized as humus. Both embodimentshave high utility on suburban home sites and small estates whichgenerate substantial quantities of such vegetation.

We claim:

1. A shredding machine comprising a hollow cylindrical shredder drumhaving an open upper end, an open lower end, an inner surface and anouter surface, a shaft coaxially journalled within said drum, at leastone shredding blade attached to said shaft and projecting laterallytherefrom, means for rotating said shaft and said shredding blade, anannular inlet spout at the upper end of said drum, coaxial with saiddrum and projecting downwardly therewithin, said spout having an outersurface, an inner surface and a bottom, there being an annular air spacebetween the outer surface of said inlet spout and the adjacent innersurface of said drum, and the bottom of said inlet spout being spacedabove the nearest shredding blade to provide a recirculation zonebetween the bottom of the spout and said blade for material which isdropped into said inlet spout to be shredded by said shredding blade anddischarged through the open lower end of the drum.

2. A shredding machine as defined in claim I and further comprisingcollecting means below said shredding blade for receiving shreddedmaterial.

3. A shredding machine as defined in claim 1 and further comprising aplurality of shredding blades attached to said shaft, said shreddingblades being angularly spaced from one another and being axially spacedfrom one another along the length of said shaft.

4. A shredding machine as defined in claim 3 wherein the ends of atleast one of said shredding blades are bent in such a way as to create adowndraft through the lower portion of said shredder drum to moveshredded material away from the bottom of said drum.

5. A shredding machine as defined in claim 1 and further comprising asafety disc attached to the end of said shaft which is nearest saidinlet spout.

6. A shredding machine as defined in claim 1 and further comprising acutting grid attached around the inner surface of said shredding drumadjacent to said shredding blade.

7. A shredding machine as defined in claim 1 and further comprising ananti-rotational stop member extending at least part way across said drumto prevent rotation of material therewithin.

8. A shredding machine as defined in claim 1 wherein said recirculationzone is relatively large with respect to said annular air space.

9. A shredding machine as defined in claim 1 and further comprisingclutch means coupled to said means for rotating said shaft to controlthe rotation thereof.

10. A shredding machine as defined in claim 1 wherein the axis of saiddrum is vertical.

1. A shredding machine comprising a hollow cylindrical shredder drumhaving an open upper end, an open lower end, an inner surface and anouter surface, a shaft coaxially journalled within said drum, at leastone shredding blade attached to said shaft and projecting laterallytherefrom, means for rotating said shaft and said shredding blade, anannular inlet spout at the upper end of said drum, coaxial with saiddrum and projecting downwardly therewithin, said spout having an outersurface, an inner surface and a bottom, there being an annular air spacebetween the outer surface of said inlet spout and the adjacent innersurface of said drum, and the bottom of said inlet spout being spacedabove the nearest shredding blade to provide a recirculation zonebetween the bottom of the spout and said blade for material which isdropped into said inlet spout to be shredded by said shredding blade anddischarged through the open lower end of the drum.
 2. A shreddingmachine as defined in claim 1 and further comprising collecting meansbelow said shredding blade for receiving shredded material.
 3. Ashredding machine as defined in claim 1 and further comprising aplurality of shredding blades attached to said shaft, said shreddingblades being angularly spaced from one another and being axially spacedfrom one another along the length of said shaft.
 4. A shredding machineas defined in claim 3 wherein the ends of at least one of said shreddingblades are bent in such a way as to create a downdraft through the lowerportion of said shredder drum to move shredded material away from thebottom of said drum.
 5. A shredding machine as defined in claim 1 andfurther comprising a safety disc attached to the end of said shaft whichis nearest said inlet spout.
 6. A shredding machine as defined in claim1 and further comprising a cutting grid attached around the innersurface of said shredding drum adjacent to said shredding blade.
 7. Ashredding machine as defined in claim 1 and further comprising ananti-rotational stop member extending at least part way across said drumto prevent rotation of material therewithin.
 8. A shredding machine asdefined in claim 1 wherein said recirculation zone is relatively largewith respect to said annular air space.
 9. A shredding machine asdefined in claim 1 and further comprising clutch means coupled to saidmeans for rotating said shaft to control the rotation thereof.
 10. Ashredding machine as defined in claim 1 wherein the axis of said drum isvertical.